Reproductive system physiology (male/female) Flashcards
What structures comprise the male reproductive system?
- Testes – the male gonads
- System of ducts
- Prostate gland
- Seminal vesicles
- Urethra
- Penis
What is the male reproductive system concerned with?
•The male reproductive system is concerned with reproduction, and also the production of testosterone, a male hormone.
Describe the location of the testes?
Contained within the scrotum – layer of loose skin and tissue divided into two by the dartos muscle.
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What are the testes for and how do they do it?
- Hormone production
- Leydig cells are found in clusters between the seminiferous tubules
- Leydig cells secrete testosterone hence the testes are part of the endocrine system
- Spermatozoa are also produced in the testes, these are produced within the seminferous tubules
What two types of cell do the seminiferous tubules contain?
What are they each for?
Spermatogenic cells – sperm forming
Sertoli cells – assist in spermatogenesis
What is the epididymis?
How long is it?
Connections?
- Tortuous canal
- About 5.5 m in length
- The efferent ducts of the testes feed into the epididymis
- The epididymis is continuous with the seminal duct
What is the seminal duct also called?
What does it continue on from?
Structure?
Where does it pass/go?
- Is also called the vas deferens
- Continuation of the epididymis
- Is tortuous initially but then straightens out
- Passes superiorly through the inguinal canal to enter the pelvis
- Passes medially to the base of the bladder
- Is joined by the duct of the seminal vesicle and forms the ejaculatory duct
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Explain spermatogenesis?
Spermatogenesis takes about 65-70 days
- The process begins with spermatogonia, these are a type of stem cell which contain the diploid number of chromosomes (2n), these are found near the basement membrane of seminiferous tubule.
- These can under go differentiation to become primary spermatocytes, these still have 46 chromosomes.
- The primary spermatocyte replicates its DNA, this gets shuffled, the cell then divides in two, each new cell having only one chromosome from chromosome pair (n). These cells are called secondary spermatocytes.
- Each chromosome is made up of two chromatids, these separate as the cell divides again, these cells are called spermatids.
- During the final stage the spermatid develops into a sperm cell.
- The above process is continuous and a male will produce about 300 million sperm each day!
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What does the spermatic cord do?
What does it contain?
What’s it surrounded by?
- Suspends the testes in the scrotum
- Contains the testicular artery, testicular veins, lymphatic vessels, the vas deferens (deferent duct) and testicular nerves
- The cord is surrounded by a sheath of smooth muscle
What do seminal vesicles do?
What are their layers?
•Secretes seminal fluid
- Outer areolar coat
- Middle smooth muscle layer
- Inner mucous layer which is lined with columnar epithelium
- The diverticula contain goblet cells which secrete most of the seminal fluid
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What are the seminal vesicles?
2 sacs, about 5 cm long
Lie on the posterior aspect of the base of the bladder
Composed of a single coiled tube which gives rise to several diverticula
Combines with the seminal duct to form the ejaculatory duct
How long are the ejaculatory ducts?
Where are they formed?
Where do they go?
About 2 cm long
Formed where the seminal duct (vas deferens) and the seminal vesicle unite
Travels inferiorly and anteriorly and enters the prostate gland
Opens into the prostatic part of the urethra
What is the Prostate gland and what does it do?
Layers?
Change in size?
Exocrine gland Provides ~ 25- 30% of ejaculate
Outer fibrous coat
Middle smooth muscle layer
Inner layer of columnar epithelium
Increases in size from birth slowly, but growth expands around puberty until age 30, after age 45 further enlargement may occur
What are Cowper’s glands?
Cowper’s glands- secrete seminal fluid- about 5% (clear fluid that enriches the seminal fluid)
Small exocrine glands
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What is the function of the prostate gland?
Function to excrete milky slightly acidic fluid, containing citric acid for the sperm to fuel the generation of ATP, proteolytic enzymes and seminal-plasmin which has an anti-biotic effect.
The prostatic secretions make up about 25% of the volume of semen.
What is the function of the epididymis?
Epididymis- function- sperm maturation and storage
What is the function of the ductus deferens?
Ductus deferens- function- conveys sperm during sexual arousal from epididymis toward urethra
What is the function of the ejaculatory ducts?
Ejaculatory Ducts- they eject sperm and seminal vessel secretions into the prostatic urethra.
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What structures comprise the female reproductive system?
Ovaries – the female gonads
Fallopian tubes (uterine tubes)
Uterus
Cervix
Vagina
What is the female reproductive system concerned with?
•The female reproductive system is concerned with reproduction, and also the production of oestrogen, a female hormone.
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Layers of the fallopian tubes?
Composed of three coats:
- Outer serous coat which is provided by the peritoneum
- Middle smooth muscle coat – outer longitudinal and inner circular fibres (moves ova by peristalsis)
- Inner mucous membrane – lies in longitudinal folds and is covered by ciliated epithelium (assists with moving the ova)
Where do the fallopian tubes lie?
How long are they?
What are it’s 4 parts?
- Lie in the upper margins of the broad ligaments of the uterus
- About 10 cm long
- Transmit the ovum from the ovary to the uterus
- Divided for descriptive purposes into 4 parts: the infundibulum, ampulla, isthmus, uterine portion
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What are the layers of the uterus?
Composed of three coats:
- An serous coat, provided by the peritoneum
- A middle muscular coat – the myometrium, forms the bulk of the uterus, composed of smooth muscle
- Inner mucous coat – the endometrium, continuous with the mucous membranes of the fallopian tubes and vagina, lined with columnar epithelium and contains numerous uterine glands
Describe the uterus?
•Hollow muscular organ
Divided for descriptive purposes into two parts:
- The body of the uterus
- The cervix of the uterus
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What are the broad ligaments of the uterus?
Folds of peritoneum
- Pass from each side of the uterus to the lateral walls of the pelvis
- The fallopian tubes lie within the superior free edge of the broad ligament
What are the round ligaments of the uterus?
Narrow fibrous bands
- Attach to the uterus just below the fallopian tubes
- Run between the layers of the broad ligament to the lateral pelvic wall
- From the lateral pelvic wall the round ligaments run anteriorly
- They pass through the inguinal canal and blend with the areolar tissue of the vulva
What are the anterior and posterior ligaments of the uterus?
Folds of peritoneum
- The anterior ligaments attach the uterus to the bladder
- The posterior ligaments attach the uterus to the rectum
- Two fibrous bands arise from the cervix, run either side of the posterior ligament, and attach to the sacrum
What is the vagina?
Layers?
The Vagina
- Fibromuscular canal
Outer loose areolar layer
- vessels and nerves
Middle smooth muscle layer
Inner mucous membrane layer
- rugae
- stratified squamous epithelium
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Oestrogen and Progesterone
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Luteinizing hormone, Follicle stimulating hormone
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What’s the 1st part of the cycle?
In the first part of the cycle estrogen stimulates the growth of the uterine lining
What’s the 2nd part of the cycle?
In the second part of the cycle progesterone stimulates the secretion from the endometrium of glycogen and other nutrients, preparing the uterine lining for implantation.
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Events in ovulation?
At the start of the cycle some secondary follicles begin to secrete estrogen and inhibin.
- By about day 6, a single follicle in one of the ovaries will out grow all the others.
- This becomes a mature (graafian) follicle, this will enlarge to a blister on the ovary of more than 2 cm in diameter, oestrogen production will increase.
- The rupture of the follicle or OVULATION occurs at about day 14. It is high levels of luteinising hormone that induce rupture and release of the egg (secondary oocyte)
Events following ovulation
Corpus luteum cells, which form following rupture, secretes progesterone, oestrogen, relaxin and inhibin
If the egg is not fertilised the corpus luteum lasts for about 2 weeks, degenerating and stopping the secretion of hormones.
If the egg is fertilised then the corpus luteum persists, due to the production of the hormone human chorionic gonadotropin (hCG), from the chorion of the human embryo from about 8 days from fertilisation.
Rules associated to imaging possibly pregnant women?
FOR WOMEN OF CHILD BEARING AGE 12-55 YOU NEED TO BE AWARE OF THE 10 and 28 DAY RULES
•All female patients MUST be asked the date of their last menstrual period.
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•If it was more than 10 days ago, you MUST ask them if there is any possibility they might be pregnant.
- Although the risk of damage to a foetus from radiological examinations in the first two weeks of gestation is minimal, high dose examinations such as CT scans of the pelvis or abdomen or barium enemas should not be conducted beyond day 10 of the cycle.
If it was more than 28 days since the patients last menstruation, a pregnancy test should be carried out.
- You may see hCG positive or negative on a form requesting a X-ray, this refers to Human Chorionic Gonadotropin. The pregnancy test relies on the detection of this hormone, which is produced in sufficient amounts in the first weeks of pregnancy to be detectable at ~ day 24 of the cycle i.e. before a period is missed.
What are the female breasts?
- Accessory organs of the female reproductive system
- Develop after puberty
- Are only fully functional at the latter stages of pregnancy and immediately following childbirth
- Are present in an undeveloped form in the male
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What 3 things is the mature mammary gland composed of?
Composed of:
- Glandular tissue
- Fibrous tissue
- Fatty tissue
How many lobes is the breast composed of?
Composed of 15 – 20 lobes
Explain the structure of the breast?
Composed of 15 – 20 lobes
Each lobe is subdivided into lobules
Each lobule contains numerous secretory alveoli
The secretory alveoli open into branches of the lactiferous ducts
Each lobe is drained by one lactiferous duct which passes up towards the areola
The lactiferous ducts form dilated sinuses near the areola which store the milk for lactation
The sinuses open by individual orifices onto the surface of the nipple
Covered by subcutaneous fascia
This fascia extends inwards to form numerous fibrous septa
These fibrous septa support the lobules
Fibrous strands also extend to the nipple and areolar
Fatty tissue lies over and between the lobes of the breast
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What is lactation associated with?
•Associated with pregnancy and childbirth
Functions of mammary glands?
Possible problem imaging?
The functions of the mammary glands are the synthesis, secretion and ejection of milk
- Milk production is stimulated primarily by the hormone prolactin, which is produced by the anterior pituitary gland.
- The ejection of milk is stimulated by the hormone oxytocin, which is released from the posterior pituitary in response to a baby suckling.
*CERTAIN IMAGING PROCEDURES INVOLVE THE USE OF RADIOACTIVE ISOTOPES, THEREFORE, IT IS ESSENTIAL TO ASK WOMEN OF CHILDBEARING AGE IF THEY ARE BREAST FEEDING AS IT IS POSSIBLE THEIR MILK MAY BE CONTAMINATED FOR A FEW DAYS.
